Adding machine



May 25, 1.926. 1,585,675 G. N. MINDLING ADDING MAc m Filed May 20, 1924 Y mvamsm- Patented May 25, 1926.

UNITED STATES GROVER N. MINDLING, OF PITTSBURGH, PENNSYLVANIA.

ADDING MACHINE.

Application filed May 20, 1924. Serial No. 714,587.

Generally speaking, my adding machine is of the hand or pocket type, wherein the products are indicated by ordinals arranged on rotatable disks and displayed at sightapertures, the disks coacting through toothed engagement.

The object which I have in view is the provision of an adding machine of such character which will be of inexpensive construction; by means of which the products of addition may be rapidly and accurately ascertained, and which may be readily cleared or returned to 0 after a column total has been obtained and noted.

In the accompanying drawings wherein I have indicated the preferred embodiment of the principles of my invention, Fig. 1 is a face view of my improved adding ma chine, the same being cleared or turned to 0; Fig. 2 is a similar view but with the face plate removed to ShOW the disks, and Fig. 3 is a. view similar to Fig. 2 but indicating the coaction of the disks in obtaining the products of addition.

The following is a detailed description of the drawings.

A representsa shallow metal casing whose front is closed by the face plate B. The face plate is provided with circular openings as 1 and 2 equal in number to the disks which are provided. The disks shown as two in the drawings and distinguished by C and D are rotatably mounted on studs 3 rigid with the case A. Said disks are so positioned and are of such diameter that their center portions are exposed by theholes l and 2, while their outer or perimetral portions are concealed by the edges of said holes.

I show in the drawings but two of said disks, one for digits and one for tens, but it will be understood that if so desired disks for tens above the capacity of the second disk or for hundreds and thousands, etc., may be provided. However, as my invention is particularly intended as a' pocketadding machine, I prefer to use but two disks, one for digits, and the other for tens up to the capacity of the latter disk.

The disk C is the digit disk, having arranged on its face adjacent to its perimeter the concentrically disposed series of ordinals O to 9 inclusive, progressing counterclockwise, said ordinals being concealed by the edge of the circular hole 1 except at its top center where the edge of the hole is notched to form the sight-aperture 5 which is guarded at the front, that is in the direction of the clockwise or normal rotation of the disk C, by the inwardly extending stop 6. The disk C is provided with a concentric series of holes 7 corresponding in numher to the ordinals and stepped inwardly from the same, into one of which holes the point of a pencil may be inserted for the purpose of rotating the disk to expose the proper ordinal at the sight-aperture. The holes are set at a proper radial distance from the axis of the disk so that when the disk is revolved clockwise by means of a pencil point inserted in one of said holes its rotation will be halted when the pencil strikes the stop 6 and the ordinal corresponding to the hole engaged by the pencil will be exposed at the sight-aperture 5. The edge of the hole 1 is provided with a series of ordinals progressing counterclockwise from 1 to 9, the position of the ordinal 0 being occupied by the sight-aperture 5. The digit disk thus is rotated clockwise in adding and counterclockwise in clearing or returning the adding machine to 0 after a column or group of numeral amounts have been added and their product noted. The second disk D, which isthe tens disk, is provided with a concentric series of ordinals running con-- secutively from 0 to as high a number as can be conveniently accommodated on the disk, which in the drawings is 19. Said ordinals progress clockwise on the disk D. These ordinals are concealed by the edge of the hole 2, except at the top center where the edge of said hole is notched to form the sight-aperture 8 guarded in the direction of rotation of the disk D which is counterclockwise by the stop 9.

The disk D is prevented from reversal or clockwise rotation. by the spring pawl 10.

The disk D has a toothed perimeter, a tooth corresponding to each of the series of ordinals upon the disk. The disk C is provided with a single tooth which meshes once in every complete revolution of the disk C with one of the teeth of the disk D, thus rotating the latter disk D one ordinal for every complete revolution of the digit disk G. Thus the digits are indicated on the disk C and the tens on the disk D. The teeth on the disk D are so disposed in relation to the corresponding ordinals that when one of said teeth is engaged and moved by the tooth on the disk C, the corresponding 0rdinal on the disk D comes into registry with the sight-aperture 8. The single tooth of the disk C is so located, as shown in Fig.

that it the disk C be rotated counterclockwise until its ordinal 0 appears at the top at the sight-aperture 5, the single tooth of said disk will be engaged by one of the teeth of the disk D, thus automatically limiting the reversal of the disk C to 0 as the disk D is incapable of clockwise rotation.

The disk D is prorided with a slotted opening ll radially alined .with the ordinal ll, and into which opening a pencil point may be insertce, so that the tens disk D may he rotated coxinterclocltwise to 0 when the machine is to be cleared. The disk D will autoi'natica ll stop at U when beingclcared the pencil point will then strik-eagainst the stop 9. If however, an amount is to be carried over on the tens disk, to be added to the next column, the pencil point is moved inwardly along the slot ll so as to escape engagement: with the stop 9, thereby permitting the tens disk to be t irned further until the proper ordinal is exposed.

\l hen a column 0t figures is to be added both disks are set, as shown in l, with 0 exposed at the sight-apertures. Then starting at the top of the right. hand col- 1mm of figures the operator places his pencil in the hole 7 ot the disk C opposite to the ordinal on the edge of said hole which corresponds to the top ligure in the column to be added, and then with his pencil rotates the disk C clockwise until his pencil strikes the stop 6 when the ordinal corresponding to the number will appear at the sight-aperture 5. The operator then lifts his pencil from the hole and replaces it in the hole corresponding to the ordinal on the edge of the hole 1 which corresponds to the next figure in the column. He then again rotates the disk C until his pencil is halted by the stop 6, whereupon the total will appear exposed the sight-aperture 5 unless the total is more than 9, in which latter case the disk C will have accomplished in the two operations at least a complete revolution, thereby advancing the disk D counterclockwiseso that the tens ordinal will appear at the sight-aperture 8 while the digit ordinal will appear at the sight-aperture o. In like manner all the numbers in the column will be added until the column is completed or until the capacity of the adding machine is reached, which capacity in the machine shown is 199. lVhen the addition of a column has been completed the total is read from the two sight-apertures and is noted, the machine is then cleared, the disk C be ingr cleared by the insertion of a pencil point inone ot the holes 7 and the rotation of the disk in a counter-cloclnvise direction until its single tooth is locked, as shown in Fig. 2, by engagement with a tooth ol? the disk D, whereupon the ordinal 0 will be displayed at the sight-aperturev 5. The disk D then cleared to 0 by the insertion of a pencil point in the slot ll and the rotation oi said disk in a counter-clockwise direction until the pencil strikes against the stop 9 when 0 will be displayed at the sightaperture 8.

The machine is now cleared and ready for the addition of the second column, the tens which were indicated previously on the disk D being added as the tirst item in the second column in like manner as above described.

The adding machine being tlat may he slid down the column like a ru er, and thus there is no dang r ot sl-zip aing a number.

in addin a long column of which the total exce 199 it is necessary to carry twenty tor each time the machine completes a total of E99 and begins to repeat. This amount or amounts ot'twenty are added to the total shown by the tens disk when the bottom oi the column is reached. For example, it the machine during the addition oi the column has passed a total of 199 once and shows 1:76 when the column is complot-ed, twei'ity will be added to the indication on the disk D at the end of the column, giving a total oi" 356, which would be the correct addition tor the entire column.

In case "he amount to be carried over to the next column is greater than a digit only, when the tens disk is cleared, the pencil is slid inwardly along the slot 11 so as to escape the stop S). thus permitting the tens disk to be moved until the tens amount to be carried is exposed at the sight-aperture.

It is apt arent t'rom the toregoing that the machine is extremely simple in construction, is accurate in its additions, can be readily cleared without close attention or adjustment, and is *apable of adding accurately and expeditiously columns totalling any amount.

Vhat I desire to claim is In a calculating machine comprising a relatively flat casing, a numeral disk rotatably mounted within the casing, having a portion of its face exposed through an opening in the casing, and having an elongated stylus opening therein wholly exposed through the casing opening. an abuti'uent on the casing projecting over the exposed surface of the disk and terminating short of the inner end of the elongated stylus opening, said abutment being adapted to arrest the disk in zero position when a stylus is inserted in the elongated opening and the disk rotated to bring the stylus into engagement with the abutment. l

Signed at Pittsburgh, Pa, this 16th day o'l lllay, 1924.

GROVER N. MINDLING. 

